Reduction of Potential Risk for Skin Toxicity in Megavoltage Radiotherapy Using a Novel Rigid Couch.

Abstract

In this study, we clarified changes of the surface dose to a low-density material on a carbon couch and verified whether a novel rigid couch (HM couch) could reduce the surface dose. We measured the surface dose using only a carbon couch (iBeam Couchtop STANDARD; BrainLab), a low-density material (Styrofoam board) on the carbon couch, and an HM couch for 6 and 10 MV photon beams. A 5-cm styrofoam board placed on the carbon couch reduced the surface dose by approximately 7-9%, while it had no impact on the depth dose profile; however, in use, such a thickness may cause collision of the patient with the gantry head. The HM couch reduced the surface dose by approximately 7-9% and shifted the depth dose profile by approximately 0.4 cm in the depth direction compared to the carbon couch. The HM couch has the potential to reduce skin toxicity and is expected to be useful in clinical practice instead of carbon couches.